package cn.feng.thinkInJava.a9_3_容器.Set;

//: containers/TypesForSets.java
// Methods necessary to put your own type in a Set.
import java.util.*;

/**
 * 基类只存储int
 */
class SetType {
	int i;

	public SetType(int n) {
		i = n;
	}

	public boolean equals(Object o) {
		return o instanceof SetType && (i == ((SetType) o).i);
	}

	public String toString() {
		return Integer.toString(i);
	}
}

class HashType extends SetType {
	// 添加了hashCode()方法
	public HashType(int n) {
		super(n);
	}

	public int hashCode() {
		return i;
	}
}

// 实现了Comparable接口
class TreeType extends SetType implements Comparable<TreeType> {

	public TreeType(int n) {
		super(n);
	}

	public int compareTo(TreeType arg) {
		// 不使用 形式return i-i2,因为这又一个常见的编程错误,他只有在i和i2都是无符号的int时候
		//才可以正确工作,对于Java有符号的int,就会出错,因为int不够大,不足以表现两个有符号的int差.
		//例如i是很大的正整数,而j是很大的负整数,i-j就会 溢出并且返回负值,就不正确了.
		return (arg.i < i ? -1 : (arg.i == i ? 0 : 1));
	}
}

public class TypesForSets {
	//使用泛型避免重复代码
	static <T> Set<T> fill(Set<T> set, Class<T> type) {
		try {
			for (int i = 0; i < 10; i++)
				set.add(type.getConstructor(int.class).newInstance(i));
		} catch (Exception e) {
			throw new RuntimeException(e);
		}
		return set;
	}

	static <T> void test(Set<T> set, Class<T> type) {
		fill(set, type);
		fill(set, type); // Try to add duplicates
		fill(set, type);
		System.out.println(set);
	}

	public static void main(String[] args) {
		test(new HashSet<HashType>(), HashType.class);
		test(new LinkedHashSet<HashType>(), HashType.class);
		test(new TreeSet<TreeType>(), TreeType.class);
		// Things that don't work:
		test(new HashSet<SetType>(), SetType.class);
		test(new HashSet<TreeType>(), TreeType.class);
		test(new LinkedHashSet<SetType>(), SetType.class);
		test(new LinkedHashSet<TreeType>(), TreeType.class);
		try {
			test(new TreeSet<SetType>(), SetType.class);
		} catch (Exception e) {
			System.out.println(e.getMessage());
		}
		try {
			test(new TreeSet<HashType>(), HashType.class);
		} catch (Exception e) {
			System.out.println(e.getMessage());
		}
	}
} /*
 * Output: (Sample) [2, 4, 9, 8, 6, 1, 3, 7, 5, 0] [0, 1, 2, 3, 4, 5, 6, 7, 8,
 * 9] [9, 8, 7, 6, 5, 4, 3, 2, 1, 0] [9, 9, 7, 5, 1, 2, 6, 3, 0, 7, 2, 4, 4, 7,
 * 9, 1, 3, 6, 2, 4, 3, 0, 5, 0, 8, 8, 8, 6, 5, 1] [0, 5, 5, 6, 5, 0, 3, 1, 9,
 * 8, 4, 2, 3, 9, 7, 3, 4, 4, 0, 7, 1, 9, 6, 2, 1, 8, 2, 8, 6, 7] [0, 1, 2, 3,
 * 4, 5, 6, 7, 8, 9, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9]
 * [0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 0, 1, 2, 3, 4,
 * 5, 6, 7, 8, 9] java.lang.ClassCastException: SetType cannot be cast to
 * java.lang.Comparable java.lang.ClassCastException: HashType cannot be cast to
 * java.lang.Comparable
 */// :~
